added subsampling

Author: awxkee

.swiftpm/xcode/xcuserdata/radzivonbartoshyk.xcuserdatad/xcschemes/xcschememanagement.plist

@@ -17,7 +17,7 @@
 		<key>JxlCoder.xcscheme_^#shared#^_</key>
 		<dict>
 			<key>orderHint</key>
-			<integer>0</integer>
+			<integer>1</integer>
 		</dict>
 		<key>jxlcoder.xcscheme_^#shared#^_</key>
 		<dict>

Sources/JxlCoder/JXLCoder.swift

@@ -34,27 +34,27 @@ public class JXLCoder {
     /***
      - Returns: Decoded JXL image if this is the valid one
      **/
-    public static func decode(srcStream: InputStream) throws -> JXLPlatformImage {
-        return try shared.decode(srcStream)
+    public static func decode(srcStream: InputStream, sampleSize: CGSize = .zero) throws -> JXLPlatformImage {
+        return try shared.decode(srcStream, sampleSize: sampleSize)
     }
 
     /***
      - Returns: Decoded JXL image if this is the valid one
      **/
-    public static func decode(url: URL) throws -> JXLPlatformImage {
+    public static func decode(url: URL, sampleSize: CGSize = .zero) throws -> JXLPlatformImage {
         guard let srcStream = InputStream(url: url) else {
             throw NSError(domain: "JXLCoder", code: 500,
                           userInfo: [NSLocalizedDescriptionKey: "JXLCoder cannot open provided URL"])
         }
-        return try shared.decode(srcStream)
+        return try shared.decode(srcStream, sampleSize: sampleSize)
     }
 
     /***
      - Returns: Decoded JXL image if this is the valid one
      **/
-    public static func decode(data: Data) throws -> JXLPlatformImage {
+    public static func decode(data: Data, sampleSize: CGSize = .zero) throws -> JXLPlatformImage {
         let srcStream = InputStream(data: data)
-        return try shared.decode(srcStream)
+        return try shared.decode(srcStream, sampleSize: sampleSize)
     }
 
     /***

Sources/jxlc/JxlInternalCoder.h

@@ -40,7 +40,7 @@ typedef NS_ENUM(NSInteger, JXLCompressionOption) {
 };
 
 @interface JxlInternalCoder: NSObject
-- (nullable JXLSystemImage *)decode:(nonnull NSInputStream *)inputStream error:(NSError *_Nullable * _Nullable)error;
+- (nullable JXLSystemImage *)decode:(nonnull NSInputStream *)inputStream sampleSize:(CGSize)sampleSize error:(NSError *_Nullable * _Nullable)error;
 - (CGSize)getSize:(nonnull NSInputStream *)inputStream  error:(NSError *_Nullable * _Nullable)error;
 - (nullable NSData *)encode:(nonnull JXLSystemImage *)platformImage
                  colorSpace:(JXLColorSpace)colorSpace

Sources/jxlc/JxlInternalCoder.mm

@@ -29,6 +29,7 @@
 #import "JxlWorker.hpp"
 #import <Accelerate/Accelerate.h>
 #import "RgbRgbaConverter.hpp"
+#import "RgbaScaler.h"
 
 static void JXLCGData16ProviderReleaseDataCallback(void *info, const void *data, size_t size) {
     auto dataWrapper = static_cast<JXLDataWrapper<uint16_t>*>(info);
@@ -160,7 +161,9 @@ - (CGSize)getSize:(nonnull NSInputStream *)inputStream  error:(NSError *_Nullabl
     return CGSizeMake(width, height);
 }
 
-- (nullable JXLSystemImage *)decode:(nonnull NSInputStream *)inputStream error:(NSError *_Nullable * _Nullable)error {
+- (nullable JXLSystemImage *)decode:(nonnull NSInputStream *)inputStream
+                         sampleSize:(CGSize)sampleSize
+                              error:(NSError *_Nullable * _Nullable)error {
     int buffer_length = 30196;
     std::vector<uint8_t> buffer;
     buffer.resize(buffer_length);
@@ -212,6 +215,17 @@ - (nullable JXLSystemImage *)decode:(nonnull NSInputStream *)inputStream error:(
         return nil;
     }
 
+    if (sampleSize.width > 0 && sampleSize.height > 0) {
+        auto scaleResult = [RgbaScaler scaleData:outputData width:(int)xSize height:(int)ySize
+                                       newWidth:(int)sampleSize.width newHeight:(int)sampleSize.height
+                                       components:components pixelFormat:useFloats ? kF16 : kU8];
+        if (!scaleResult) {
+            *error = [[NSError alloc] initWithDomain:@"JXLCoder" code:500 userInfo:@{ NSLocalizedDescriptionKey: @"Rescale image has failed" }];
+            return nil;
+        }
+        xSize = sampleSize.width;
+        ySize = sampleSize.height;
+    }
 
     CGColorSpaceRef colorSpace;
     if (iccProfile.size() > 0) {

Sources/jxlc/JxlWorker.cpp

@@ -62,7 +62,7 @@ bool DecodeJpegXlOneShot(const uint8_t *jxl, size_t size,
     JxlDecoderSetUnpremultiplyAlpha(dec.get(), JXL_TRUE);
 
     JxlBasicInfo info;
-    JxlPixelFormat format = {4, JXL_TYPE_UINT8, JXL_LITTLE_ENDIAN, 0};
+    JxlPixelFormat format = {4, JXL_TYPE_UINT8, JXL_NATIVE_ENDIAN, 0};
 
     JxlDecoderSetInput(dec.get(), jxl, size);
     JxlDecoderCloseInput(dec.get());
@@ -98,7 +98,7 @@ bool DecodeJpegXlOneShot(const uint8_t *jxl, size_t size,
             if (bitDepth > 8) {
                 *useFloats = true;
                 hdrImage = true;
-                format = { static_cast<uint32_t>(baseComponents), JXL_TYPE_FLOAT16, JXL_LITTLE_ENDIAN, 0 };
+                format = { static_cast<uint32_t>(baseComponents), JXL_TYPE_FLOAT16, JXL_NATIVE_ENDIAN, 0 };
             } else {
                 format.num_channels = baseComponents;
                 *useFloats = false;

Sources/jxlc/RgbaScaler.h

@@ -0,0 +1,54 @@
+//
+//  RgbaScaler.h
+//  JxclCoder [https://github.com/awxkee/jxl-coder-swift]
+//
+//  Created by Radzivon Bartoshyk on 27/09/2023.
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+//
+
+#ifndef RgbaScaler_h
+#define RgbaScaler_h
+
+#ifdef __cplusplus
+
+#import <vector>
+
+typedef NS_ENUM(NSInteger, JxlIPixelFormat)  {
+    kU8 NS_SWIFT_NAME(Uniform8),
+    kF16 NS_SWIFT_NAME(Float16)
+};
+
+@interface RgbaScaler : NSObject
+/**
+ * Converts unsigned uint8_t RGBA to RGB in uint8_t.
+ * @author Radzivon Bartoshyk
+ *
+ * @param srcVector Source buffer
+ * @param width width of of the image
+ * @param height width of of the image
+ * @param pixelFormat Pixel Format of the image
+ * @return destination
+ */
++(bool) scaleData:(std::vector<uint8_t>&)src width:(int)width height:(int)height newWidth:(int)newWidth newHeight:(int)newHeight components:(int)components pixelFormat:(JxlIPixelFormat)pixelFormat;
+@end
+
+#endif
+
+#endif /* Header_h */